1. Field of the Invention
The present invention relates to a closure suitable for attachment directly or indirectly to a container neck sealed by a pierceable membrane or film. The provision of a membrane or film sealing the open neck of the container guarantees the user that the contents of the container are authentic and original as supplied by the manufacturer. Furthermore, by insuring the exclusion of air from the contents, this film also helps to prevent oxidation of the product.
2. Description of the Prior Art
A simple form of closure is known, which is provided with a cap screwed onto the container neck, whereby a film covers the open neck of the container, which film can be pierced manually or with the help of a tool. Closures of this type provide no guarantee that the contents have not been tampered with unless the user takes the trouble to check the contents. For this purpose, the user has to unscrew the cap.
Screw closures which are protected against initial removal provide better protection for the user. Screw closures of this type are known. In order to prevent a cap of this type from coming unscrewed of its own accord, it is provided with a safety band which engages in ratchet-like serrations provided around the neck of the container. This arrangement insures that the screw cap cannot be removed without breaking the safety band. In fact, this cap cannot be unscrewed until the safety strip has first been torn off and removed. Arrangements of this type are described in German Patent Publications DE-A Nos. 24 56 931; 29 04 181; 29 23 379; 29 52 778; and 32 02 226, for example.
A further development of this type of arrangement is described in European Patent EU-PS No. 0050 490. Once the safety band has been removed the cap can be unscrewed, whereby it engages under the edge of an upper part of the container neck and can be snapped off. As soon as the cap is unscrewed for the first time, the part which snaps off is torn away from the container neck by rotating the cap.
All the prior art teachings for improving the safety of containers to insure that the contents are intact and have not been tampered with directly conflict with the objective of providing the required degree of user convenience. For the user to be able to make use of the contents of a container, the closure must first be unscrewed and then screwed back onto the container after use. There is also the risk of the cap being lost, so that the container can no longer be closed properly, thus allowing its contents to spoil or the quality to suffer.